How the screens handle smudge marks, scratching, being pressed up onto each other. Will they shatter if you accidentally close the book with pen between the screens?

How long the battery lasts.

How hot it gets on your lap.

If it can connect to the computer we use. (Mac or PC.)

Etc.

In other words, it's nice to get excited about a drawing of a fantasy product. We'd all love a cheap, digital booklet that takes pictures and loads maps super-fast over the Internet.

But let's not lose touch with reality -- and Microsoft's history in the gadget industry. When's the last time Redmond actually made something that works like this? What's changed that might make this a reality now?